Dehui Fan Changsha Negative Pressure Fan Manufacturer Dehui Special Fan

With the advancement of China's industrialization process, the industrial sector is vigorously promoting energy conservation and consumption reduction, upgrading and integrating industries, and requiring a large amount of new industrial infrastructure. As an important supporting equipment in industry, centrifugal fans will be more widely used in fields such as electricity, cement, petrochemicals, coal, mining, and environmental protection. Under the new economic development situation, the centrifugal fan industry will continue to maintain rapid growth in the future. It is expected that by 2022, the market size of the centrifugal fan industry will reach 96 billion yuan.

Installation Notes
1. The installation of the centrifugal fan unit as a whole should be directly placed on the foundation and leveled with paired diagonal pads.
2. The cutting surface on the base of the centrifugal fan assembled on site should be properly protected and should not be corroded or operated. When the base is placed on the foundation, paired diagonal pads should be used to level it.
3. The bearing seat and base should be tightly connected, and the longitudinal non levelness should not exceed 0.2/1000, measured on the spindle with a spirit level. The horizontal non levelness should not exceed 0.3/1000, measured on the horizontal split of the bearing seat with a spirit level.
4. Before grinding and scraping the bearing shell, the rotor axis line and the casing axis line should be calibrated, and the gap between the impeller and the air inlet, as well as the gap between the main shaft and the rear plate shaft hole of the casing, should be adjusted to comply with the technical specifications of the equipment.
5. When assembling the main shaft and bearing, inspection should be carried out according to the technical specifications of the equipment. The interference fit between the bearing cover and the bearing shell should be maintained at 0.03-0.04 millimeters (measure the outer diameter of the bearing shell and the inner diameter of the bearing seat).
6. When assembling the fan casing, the position of the casing should be aligned based on the rotor axis line, and the axial and radial clearances between the impeller inlet and the casing inlet should be adjusted to the range specified in the equipment technical documents at high speed. At the same time, the anchor bolts should be checked for tightness. When the clearance value is not specified in the equipment technical documents, the axial clearance should generally be 1/100 of the outer diameter of the impeller, and the radial clearance should be evenly distributed, with a value of 1.5/1000 to 3/1000 of the outer diameter of the impeller (whichever is smaller, take the larger value). When adjusting, strive for a smaller gap value to improve the efficiency of the fan.
7. When aligning the fan, the different axial degrees between the fan shaft and the motor shaft should not exceed 0.05 millimeters for radial positioning and 0.2 millimeters for inclination.
8. The centrifugal fan assembled with rolling bearings has different axial degrees of the bearing holes on the two bearing frames. After the rotor is installed, the flexibility of rotation shall prevail

Shanghai Dehui centrifugal fan is based on the principle of converting kinetic energy into potential energy, using a high-speed rotating impeller to accelerate gas, then decelerate and change the flow direction, converting kinetic energy into potential energy (pressure).
In a single-stage centrifugal fan, gas enters the impeller from the axial direction, changes to the radial direction as it flows through the impeller, and then enters the diffuser.
In the diffuser, the gas changes its flow direction and the cross-sectional area of the pipeline slows down the airflow, which converts kinetic energy into pressure energy.
The increase in pressure mainly occurs in the impeller, followed by the expansion process. In a multi-stage centrifugal fan, a reflux device is used to direct the airflow into the next impeller, generating high pressure.

Common types
The commonly used types of centrifugal fans are as follows:
1. Industrial centrifugal fan
2. Dust removal/environmental protection fan
3. Anti corrosion/explosion-proof fan
4. High temperature boiler induced draft fan